1. Field of the Invention
The invention relates to a direct-current electric-arc furnace comprising a furnace vessel, which is provided with a metallic shell, at least one electrode connected as cathode, and at least one bottom contact, the bottom of the furnace consisting of a lining layer which has electrically conductive bricks or other identically acting inserts, which lining layer rests on a bottom plate together with which it forms the bottom contact connected as anode, the bottom contact being insulated from the metallic shell of the furnace vessel by insulating material.
The invention makes reference here to a prior art as results, for example, from U.S. Pat. No. 4,228,314.
2. Discussion of Background
In direct-current electric-arc furnaces, both the electrode connected as cathode and the hearth or bottom electrode, which as a rule is constructed as a bottom contact, e.g. according to U.S. Pat. No. 4,228,314, must be insulated from the metallic shell of the furnace vessel. In the known electric-arc furnace, the bottom contact and the adjoining parts of the bottom lining rest on a metal plate. This metal plate in turn rests on a layer of insulating material on the (metallic) vessel bottom. The electrical connection of the bottom contact is made here via contact parts which are passed through openings in the vessel bottom. The insulating layer is highly stressed both by the weight of the charge and the extreme temperatures occurring during the furnace operation. Special cooling of this area is very expensive.